When the LHC is up and running the total average power for the whole CERN site will peak at about 200 MW (usually from May to mid-December), which is about a third of the amount of energy used to feed the nearby city of Geneva in Switzerland.

If we include the base load for the whole site, the LHC contribution totals around 115 MW.

During winter, when the accelerators are not running, CERN's total consumption drops to about 80 MW.

Energy.

Assuming 200 MW from May to mid-December, and 80 MW for the rest of the year:

[200 x (7.5 x 30 x 24)] +[80 x (4.5 x 30 x 24)]

Consumption ~ 1.3 TWh per year

On average, the household electricity consumption in Spain is over 3500 kWh/year, so 1.3 TWh is enough power to fuel 370000 spanish homes for a year in Spain.

But the energy consumption depends on the specific year, and it needs changes from month to month, as the seasons shift and the experimental requirements are adjusted. Precisely, after this first Long Shutdown (LS1), upgrades will increase CERN’s annual electricity bill by 20% to €60 million (US$65 million).

Let's see the 2012 CERN Electrical Power Consumption (remember that in 2013-14 CERN accelerator complex was in long shutdown).

Figures taken from the document: 2012 CERN Electrical Power Consumption EN-EL April 5th 2013

CERN does not generate any of its own power, although it does have diesel generators as back-up in the case of power cuts to run essential services. When CERN was established in 1954, a substation on the Swiss side of the campus was enough to meet the electrical needs of the laboratory.

Sixty years after that, CERN is powered from the French electrical grid through an overhead 400 kV line connected to the grid at Bois‐Tollot substation, close to CERN’s Prévessin site. This overhead line is owned by RTE, the French utility company operating the French transport grid. CERN has an energy supply contract with EDF. An additional connection from the Swiss electrical grid is used in case of emergency or during maintenance operations: this line at 130 kV is limited to 60 MVA (60 MW).

Xabier CidVidal, PhD in experimental Particle Physics for Santiago University (USC). Research Fellow in experimental Particle Physics at CERN from January 2013 to Decembre 2015. Currently, he is in USC Particle Physics Department (Spanish Postdoctoral Junior Grants Programme).

Ramon Cid Manzano, secondary school Physics Teacher at IES de SAR (Santiago - Spain), and part-time Lecturer (Profesor Asociado) in Faculty of Education at the University of Santiago (Spain). He has a Degree in Physics and in Chemistry, and is PhD for Santiago University (USC).